Molecular Pathogenesis of Liver Cancer

Early life exposure to Chinese famine and risk of digestive system cancer in midlife

To investigate whether early-life exposure to the Great Famine of 1959-1961 in China was associated with the risk of digestive system cancer. The prospective cohort study involved 17 997 participants from the Kailuan Study (Tangshan, China) that began in 2006. All participants were divided into three groups based on their date of birth. The unexposed group (born from 1 October 1962 to 30 September 1964), fetal-exposed group (born from 1 October 1959 to 30 December 1961), and early-childhood-exposed group (born from 1 October 1956 to 30 December 1958). The Cox proportional hazards model was used to analyze the association between early famine exposure and digestive system cancer. During the mean follow-up period of (10.4 ± 2.2) years, a total of 223 digestive system cancer events occurred. Including 54 cases in the unexposed group (62.14/100 000 person-years), 57 cases in the fetal-exposed group (114.8/100 000 person-years), and 112 cases in the early-childhood-exposure group (122.2/100 000 person-years). After adjusting covariates, compared with the unexposed group, the HR and 95% CI were 1.85 (1.28, 2.69) for participants in the fetal-exposed group and 1.92 (1.38, 2.66) for participants in the early-childhood-exposed group. No interactions were observed in our study. After classifying digestive system cancers, the HR and 95% CI were 2.02 (1.03, 3.97) for colorectal cancer for participants in the fetal-exposed group and 2.55 (1.43, 4.55) for participants in the early-childhood-exposed group. The HR and 95% CI were (1.13, 3.83) of liver cancer for participants in the fetal-exposed group and 1.15 (0.63, 2.10) for participants in the early-childhood-exposed group. Early-life famine exposure was associated with a higher risk of digestive system cancer in adulthood. Fetal-exposed individuals might increase the risk of colorectal cancer and liver cancer, and early childhood-exposed might increase the risk of colorectal cancer.

ViroISDC: a method for calling integration sites of hepatitis B virus based on feature encoding

BACKGROUND

Hepatitis B virus (HBV) integrates into human chromosomes and can lead to genomic instability and hepatocarcinogenesis. Current tools for HBV integration site detection lack accuracy and stability.

RESULTS

This study proposes a deep learning-based method, named ViroISDC, for detecting integration sites. ViroISDC generates corresponding grammar rules and encodes the characteristics of the language data to predict integration sites accurately. Compared with Lumpy, Pindel, Seeksv, and SurVirus, ViroISDC exhibits better overall performance and is less sensitive to sequencing depth and integration sequence length, displaying good reliability, stability, and generality. Further downstream analysis of integrated sites detected by ViroISDC reveals the integration patterns and features of HBV. It is observed that HBV integration exhibits specific chromosomal preferences and tends to integrate into cancerous tissue. Moreover, HBV integration frequency was higher in males than females, and high-frequency integration sites were more likely to be present on hepatocarcinogenesis- and anti-cancer-related genes, validating the reliability of the ViroISDC.

CONCLUSIONS

ViroISDC pipeline exhibits superior precision, stability, and reliability across various datasets when compared to similar software. It is invaluable in exploring HBV infection in the human body, holding significant implications for the diagnosis, treatment, and prognosis assessment of HCC.

MicroRNA-155 downregulates long noncoding RNA prostate cancer-associated transcript 29 in hepatocellular carcinoma to suppress cancer cell invasion and migration

Long noncoding RNA (lncRNA) prostate cancer-associated transcript 29 (PCAT29) is known to suppress several cancers, but its participation in hepatocellular carcinoma (HCC) remains elusive. This study tried to explore PCAT29 function in HCC. In this study, a total of 62 HCC patients were enrolled. Tissue samples were collected from all 62 patients to isolate RNA samples. Quantitative reverse transcription polymerase chain reaction was applied for the expression analysis of PCAT29 and microRNA-155 (miR-155) in these tissue samples. The 62 HCC patients were followed up for 5 years to explore the prognostic value of PCAT29 for HCC. Correlations were analyzed using linear regression. IntaRNA 2.0 was used to predict the interaction between PCAT29 and miR-155. The role of PCAT29 and miR-155 in regulating HCC cell invasion and migration was evaluated by Transwell assay. We found that PCAT29 expression was downregulated in HCC and miR-155 expression was upregulated in HCC compared to nontumor samples (p < 0.001). Downregulation of PCAT29 was found to be closely associated with poor survival of HCC patients. MiR-155 was inversely correlated with PCAT29. It was predicted that miR-155 could target PCAT29. In HCC cells, miR-155 overexpression resulted in reduced PCAT29 expression (p < 0.05). MiR-155 counteracted the inhibitory effects of PCAT29 overexpression on HCC cell migration and invasion. These results suggest that PCAT29 may be a potential prognostic biomarker and a novel therapeutic target for treating HCC.

SCUBE3 downregulation modulates hepatocellular carcinoma by inhibiting CCNE1 via TGFβ/PI3K/AKT/GSK3β pathway

OBJECTIVES

We aimed to verify the role of signal peptide-CUB-EGF-like domain-containing protein3 (SCUBE3) in the hepatocellular carcinoma (HCC) progression.

METHODS

The role of SCUBE3 in HCC cell proliferation, apoptosis, and cell cycle in vitro were detected using MTT assay, colony formation assay, 5-ethynyl-2´-deoxyuridine assay (EDU), Celigo cell counting assay, Caspase3/7 activity assay, and flow cytometry. The effect of SCUBE3 on HCC cell proliferation in vivo was inspected by a xenograft tumour model in nude mice. The related mechanisms were further studied.

RESULTS

The level of SCUBE3 was upregulated in HCC tissues and cell lines. Knockdown of SCUBE3 inhibited proliferation, promoted apoptosis, and induced cell cycle arrest in HCC cell lines in vitro and in vivo. Screening of cell cycle-related proteins revealed that CCNL2, CDK6, CCNE1, and CCND1 exhibited a significantly different expression profile. We found that SCUBE3 may promote the proliferation of HCC cells by regulating CCNE1 expression. The pathway enrichment analysis showed that the TGFβ signalling pathway and the PI3K/AKT signalling pathway were significantly altered. Co-immunoprecipitation results showed that SCUBE3 binds to the TGFβRII receptor. SCUBE3 knockdown inhibited the PI3K/AKT signalling pathway and the phosphorylation of GSK3β to inhibit its kinase activity.

CONCLUSIONS

SCUBE3 promotes HCC development by regulating CCNE1 via TGFβ/PI3K/AKT/GSK3β pathway. In addition, SCUBE3 may be a new molecular target for the clinical diagnosis and treatment of HCC.

A novel seven-lncRNA signature for prognosis prediction in hepatocellular carcinoma

Liver cancer is still one of the leading causes of cancer-related death worldwide. This study is dedicated to developing a multi-long noncoding RNA (lncRNA) model for risk stratification and prognosis prediction on patients with hepatocellular carcinoma (HCC). We first downloaded lncRNA expression profiles and corresponding clinical information of patients with liver cancer from The Cancer Genome Atlas database. Differentially expressed (DE) lncRNAs between HCC samples and normal samples were identified. In total, 308 patients with HCC were randomly divided into a training group (n = 154) and a testing group (n = 154). Univariate Cox regression and least absolute shrinkage and selection operator Cox regression analyses were performed to select the best survival-related candidates from these DE lncRNAs in the training set. Seven lncRNAs (AC009005.2, RP11-363N22.3, RP11-932O9.10, RP11-572O6.1, RP11-190C22.8, RP11-388C12.8, and ZFPM2-AS1) were finally identified and used to construct a seven-lncRNA signature. The signature could classify patients into high-risk and low-risk groups with significantly different overall survival. The area under the curve of receiver operating characteristic curve for the signature to predict 5-year survival reached more than 0.75. Besides, the prognostic value of the seven-lncRNA signature was independent of conventional clinical factors. The predictive performance of the signature was further validated in the testing set and the whole set. Functional enrichment analysis indicated that the seven prognostic lncRNAs may be involved in several essential biological processes and pathways. The current study demonstrated the potential clinical implications of the seven-lncRNA signature for survival prediction of patients with HCC.

Liver Cancer: Molecular Characterization, Clonal Evolution and Cancer Stem Cells

Liver cancer is the second most common cause of cancer-related death. The major forms of primary liver cancer are hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (iCCA). Both these tumors develop against a background of cirrhotic liver, non-alcoholic fatty liver disease, chronic liver damage and fibrosis. HCC is a heterogeneous disease which usually develops within liver cirrhosis related to various etiologies: hepatitis B virus (HBV) infection (frequent in Asia and Africa), hepatitis C virus (HCV), chronic alcohol abuse, or metabolic syndrome (frequent in Western countries). In cirrhosis, hepatocarcinogenesis is a multi-step process where pre-cancerous dysplastic macronodules transform progressively into HCC. The patterns of genomic alterations observed in these tumors were recently identified and were instrumental for the identification of potential targeted therapies that could improve patient care. Liver cancer stem cells are a small subset of undifferentiated liver tumor cells, responsible for cancer initiation, metastasis, relapse and chemoresistance, enriched and isolated according to immunophenotypic and functional properties: cell surface proteins (CD133, CD90, CD44, EpCAM, OV-6, CD13, CD24, DLK1, α2δ1, ICAM-1 and CD47); the functional markers corresponding to side population, high aldehyde dehydrogenase (ALDH) activity and autofluorescence. The identification and definition of liver cancer stem cells requires both immunophenotypic and functional properties.